Coral base bleaching

[damura]

Hi everyone,

Does anyone here have experience with the following phenomenon:
Every few months, for some reason, i have SPS bleaching starting from the base of the coral, it progresses quiet slowly, unlike RTN, and it covers dark areas, those areas that don't receive direct light. I have the same problem with several SPS's and i fear that it will spread out to lit areas.
In past occasions it just stopped and algae grew over the dead parts. Obviously something in the water quality induced it.
i just want to hear from other amateurs about the same phenomenon, and the possible assumptions for the cause

Thanks.

[rynon]

If it's covering the dark areas of the coral it could be due to lack of flow on those areas. As corals grow they start to shade themselves AND they also block flow as they grow. Post you flow rate and tank size and we'll see if that could be the problem, or adding to the problem.